Mohammad Mahdavi Mazdeh

The aim of this paper is to study one of the classical scheduling objectives to minimizethe sum of flow times, in the context of a supply chain network. Let's consider a situation that a supplier schedules a set of jobs for delivery in batches to several manufacturers, who in turn has to schedule and deliver jobs in batches to several customers. The personal problem from the viewpoint of supplier and manufacturers will be addressed separately. The decision problem faced by the supplier is to minimize the sum of flow time and delivery cost of a set of jobs to be processed on a single machine for delivery in batches to manufacturers. The problem on the side of manufacturer is similar to the supplier’s problem and the only difference is the scheduling, batching and delivery decisions made by the supplier to define a release date for each job, before the manufacturer cannot start the processing of that job. A combined problem in the light of cooperation between the supplier and manufacturer will be addressed as well. The objective of the combined problem is to find the best scheduling, batching, and delivery decisions that benefit the entire system including the supplier and manufacturer. Computational experience shows that cooperation between a supplier and a manufacturer reduces the total system cost of up to 12.35%, while theoretically the reduction of upto 20% can be achieved in special cases.

supply chain management, scheduling, single machine, sum of flow time